Research On Three Gorges Reservoir Bedding Slope Deformation Mechanism And Stability

Bedding slope in the Three Gorges reservoir area are widely distributed, often developing a class of medium-sized landslide slope. Because along with a huge landslide occurred suddenly, endangering notable features, especially since the Three Gorges Reservoir, the probability of occurrence of old landslide greatly increased. Thus, in the Three Gorges Reservoir and the reservoir area of the Migration Project in the context of the Three Gorges Reservoir Area bedding slope deformation mechanism and stability studies, is not only practical value, but also has important social significance and theoretical Significance.In this paper, data collection, field survey, documentation and other interior work, based on a statistical analysis, geomechanical analysis, limit equilibrium analysis and numerical simulation analysis, research tools, the Three Gorges reservoir area the distribution of bedding slope start Typical old landslide by studying examples of different types of slope failure characteristics of bedding; of old landslide by analyzing the internal factors and external factors, combined with old landslide examples and discrete element modeling, analysis of different types of bedding Coast Slope deformation and failure mechanisms; to Taozi ping potential landslide along a typical example, from a quantitative point of view of the Three Gorges Reservoir outside of this new dynamic factors, the slope variation of the stability . Specific details and results are as follows:1, Through the Three Gorges reservoir area's new type of landslides and old type of landslides statistical analysis shows that: the major landslide along the Three Gorges reservoir area development level in the low-angle straight angle change bedding and bedding slope Slope section.Through the Three Gorges along the landslide typical analysis shows: the Three Gorges reservoir area within the development along the main landslide area or in the folds of the turning point in the transition parts of the syncline and anticline; landslide occurred along the slope of the slope structure is composed of hard and soft white rock or rock with weak interlayer composition; before the landslide in the bedding, bedding slope under gravity creep has occurred; before the Three Gorges Reservoir, the reservoir area development along mainly by landslide storm-induced human engineering activities.2, Three Gorges reservoir area bedding slope deformation and failure mechanisms is due to external factors of geological environment and the result of joint action. Internal factors include: lithology, topography, rock formations and changes in inclination; external factors include: reservoir water, rainfall, human engineering activities.(1) Through the landslide along the Three Gorges reservoir reached the incomplete statistics: in the Three Gorges reservoir area, development along the landslide lithology and lithologic up sand mudstone, followed by marl; development along the landslide topography is mainly reflected in elevation, the library district developing along the height distribution of the largest landslide in the 300m-400m range, followed by 200m-300m range, followed by the 400m-500m range; the reservoir area strata dip less than 20°range of development along the landslide, followed by 20°-45°range, rock angle greater than 45°along the landslide is not within the development.(2) Field survey for data collection and comprehensive analysis of obtained: the reservoir water level rose too Cheng Duishun slope is mainly reflected in the changing nature of rock and soil, resulting in uplift the two aspects of reservoir water down on the bedding Slope is mainly reflected in the production of permeate water pressure, hydrostatic pressure, excess pore water pressure in three areas; rainfall is mainly reflected in the increase of rock and soil bulk density, changing the nature of rock and soil, or between layers in the soft rock band have broken hydrostatic pressure and lateral pressure; human engineering activities, mainly in artificial cut foot, man-loading and so on.3, Through the landslide along the Three Gorges Reservoir typical case analysis and 2D-block discrete element simulation software, integrated view: Three Gorges reservoir area within the level of low-angle bedding straight slope deformation and failure mechanism of the main slip - crack Type, moderate levels of bedding dip slope straight major slip deformation and failure mechanisms - curved; lithologic and reservoir water level under the influence, and change of bedding dip slope failure mechanism for the sliding main deformation - bending - Bedding Cut out the type and sliding - crack type. 4, Taken along Taozi Ping landslide potential as a typical example, the use of transfer coefficient method and software Geo-slope method of combining method to calculate the water level in different static water level (145m, 156m, 175m), the water level to 1m / s , 5m / s speed increased, the water level to 0.6m / s, 1m / s rate of decline in the stability of the three changes in the process of the landslide. The results show that:(1) Under the static water level, the higher the water level, the worse the stability of landslide.(2)Rise in water level during storage at different speeds, decreased the stability of landslide, but the water the faster the decrease in the stability of landslide slower than in the case of water is smaller;(3) Water level in the fall at different speeds the process, the stability of the landslide has a fall and rise of the process. To 0.6m / s velocity decreases, the stability of landslide in the reservoir water level reached the lowest for the 160m, and then slowly increase; to 1m / s velocity decreases, the stability of landslide in the reservoir water level reached the lowest for the 155m, and then slowly increase . (4)The smaller the water level deceleration, the smaller the decrease in slope stability.